The present invention relates to a pumping light source drive system for an optical amplifier which is composed of a rare earth doped optical fiber and a pumping light source therefor.
The optical amplifier made up of a rare earth doped optical fiber and a pumping light source therefor has the advantages of the independency of gain from polarized light and a small coupling loss.
For example, in a case where an optical amplifier using the rare earth doped optical fiber is applied to an optical submarine cable system, a service life of about 25 years is required of the optical amplifier, but when the living pumping light source is always driven for the high-output operation as in the prior art, the optical amplifier has a relatively short life, and hence is low in reliability.